The head of a Tiger Shark during research into the biological mechanics of the predator in Sydney, Australia. (GETTY)

At first, the fishermen were excited with the massive volume of their catch: a 660-pound shark caught while on a fishing trip off the coast of Surigao, Philippines.

And then they were horrified.

The crew of five pulled the gigantic fish onto their boat and, after celebrating and probably anticipating a good payday – two pounds of shark meat goes for about $1.40 in the local market – opened the animal and got the shock of their lives. They found a human head and parts of a leg.

“It was so disgusting. We couldn’t bear the awful smell,” Bodoy Gorgod, one of the fishermen, told Minda News , a news co-operative based in Mindanao, the Philippines’ second-largest island.

The shark was caught between the waters of Bohol and Camiguin islands last week.

“We feared that the human remains may bring bad luck to us, so we opted to drop to the sea the shark’s body and what’s inside its belly,” Gorgod, 48, added.

The only things they kept were the massive jaw and fins of the fish, though the wife of another fisherman objected to the jaw, too, saying she feared the spirit of the shark’s victim might come back to haunt them.

“I don’t want the sight of that jaw, knowing that the shark had eaten a human being. Who knows – the victim’s spirit might visit us,” she told Minda News.

Some of the locals speculated that the remains could belong to one of two male passengers still missing from the wreckage of a ferry, the M/V Maharlika 2, that sank on Sept. 13 off the nearby island of Leyte.